Nuclear and particle physics Flashcards
Rutherford scattering experiment lead to discovery of…
nucleus
what do the undeflected alpha particles prove
most of the atom is empty space
what proportion of alpha particles were deflected in the experiment
1/2000
what proportion of alpha particles were deflected more than 90 degrees
1/8000
how to estimate the maximum radius of the nucleus
kinetic energy and closest approach
what is an isotope
element with same number of protons but different number of neutrons
how to work out distance of closest approach
Kinetic energy = Electric potential energy
1/2 mv^2 = Qq/4piE0r^2
nuclear radius R equation
R=r0 A^1/3
r0 is a constant (1.2x10^-15)
A is nucleon number
define hadron
a particle that experiences both the strong nuclear force and the weak nuclear force
define lepton
fundamental particles and don’t experience the strong nuclear force
antiparticle of:
proton
electron
neutron
neutrino
antiproton
positron
antineutron
antineutrino
name two hadrons
protons and neutrons
name two leptons
electrons and neutrinos
quark composition of proton
uud
quark composition of neutron
udd
diameter of atom
10^-10 m
diameter of nucleus
10^-15 m
Activity of a source
A = λN
Half life of an isotope
λt1/2 = ln2
Activity at a given time
A=A₀e^-λt
Number of undecayed nuclei
N=N₀e^-λt
Energy mass equation
E=mc^2
what is mass defect
difference between masses of products and final product
explain what is meant by the total binding energy of a nucleus
Energy required to disassemble the nucleus into protons and neutrons
What’s a moderator
material which slows down neutrons produced by fission
what’s a coolant
fluid pumped through core of a reactor to transfer thermal energy from core to the heat exchanger
What are control rods
Cadmium rods that are moved in and out of the core to absorb more/less of the neutron to control the rate of fission
Two quantities conserved in beta decay
charge
energy/mass
What is an alpha particle
Helium nucleus
Two protons, two neutrons
